Microorganisms present in soil are known to assimilate hydrocarbons but, unfortunately, at such a slow rate that natural biodegradation of hydrocarbon contaminated soil is not a practical soil remediation method. Attempts to accelerate microbial growth to enhance soil remediation typically involve providing microbial nutrient material, especially nitrogen and phosphorous containing nutrient materials to the contaminated soil. While the addition of microbial nutrients to contaminated soil is somewhat beneficial, the rate of hydrocarbon biodegradation still remains inadequate to be a totally practical soil bioremediation technique. Therefore, there remains a need for improvements in techniques for enhancing the microbial bioremediation of hydrocarbon contaminated soil.
Apparently, petroleum contaminants, and especially weathered petroleum soil contaminants, are not readily accessible to the microorganisms capable of assimilating the contaminant. Additionally, it would appear that the extent of microbial utilization of petroleum hydrocarbons is further limited by the number and activity of hydrocarbon assimilating microflora.
Accordingly, the present invention provides an improved method for enhancing the bioremediation of hydrocarbon contaminated soil by stimulating the growth and activity of naturally occurring, hydrocarbon assimilating, microflora and by rendering the hydrocarbon contaminant more accessible to the microflora.